1. Technical Field
The present invention relates to a liquid ejecting head which ejects liquid from nozzle openings and a liquid ejecting apparatus.
2. Related Art
As a piezoelectric element used in a liquid ejecting head, there is a piezoelectric element which is configured by interposing between two electrodes a piezoelectric layer formed of a piezoelectric material having an electromechanical conversion function, for example, a crystallized dielectric material. Such a piezoelectric element is mounted in a liquid ejecting head as, for example, an actuator device of a flexural vibration mode. As a representative example of a liquid ejecting head, for example, there is an ink jet recording head wherein a part of a pressure generating chamber, which communicates with nozzle openings which discharge ink, is configured by a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize ink in the pressure generating chamber, thus discharging ink droplets from the nozzle openings.
As the piezoelectric element mounted in such an ink jet recording head, for example, there is the piezoelectric element formed so as to be independent for each pressure generating chamber by forming a uniform piezoelectric material layer using film deposition technology over the entire surface of the vibrating plate, and cutting the piezoelectric material layer into shapes corresponding to the pressure generating chambers using a lithographic method (refer to JP-A-2003-127366).
In the piezoelectric element, stress acts on the piezoelectric layer when a voltage is applied, and when this happens, there is a problem in that cracks may be generated in the piezoelectric layer. In particular, in the case when the piezoelectric layer is formed as a thin film using a thin film deposition method such as a solution deposition technique or a CVD method, which is different to a so-called bulk piezoelectric layer formed by sintering grains of metal oxide, the problem of the generation of cracks becomes pronounced due to stress acting on the piezoelectric element becoming large. Here, a problem such as this is not limited to ink jet recording heads and also occurs in liquid ejecting heads which eject other liquids.